Policy Controller

The policy-controller admission controller can be used to enforce policy on a Kubernetes cluster based on verifiable supply-chain metadata from cosign.

policy-controller also resolves the image tags to ensure the image being ran is not different from when it was admitted.

See the installation instructions for more information.

Today, policy-controller can automatically validate signatures and attestations on container images. Enforcement is configured on a per-namespace basis, and multiple keys are supported.

We're actively working on more features here.

For more information about the policy-controller, have a look at our documentation website here.

Examples

Please see the examples/ directory for example policies etc.

Policy Testing

This repo includes a policy-tester tool which enables checking a policy against various images.

In the root of this repo, run the following to build:

make policy-tester

Then run it pointing to a YAML file containing a ClusterImagePolicy, and an image to evaluate the policy against:

(set -o pipefail && \
    ./policy-tester \
        --policy=test/testdata/policy-controller/tester/cip-public-keyless.yaml \
        --image=ghcr.io/sigstore/cosign/cosign:v1.9.0 | jq)

Local Development

You can spin up a local Kind K8s cluster to test local changes to the policy controller using the `` CLI tool. Build the tool with make local-dev and then run it with `./bin/local-dev setup`.

It optionally accepts the following:

--cluster-name
--k8s-version
--registry-url

You can clean up the cluster with ./bin/local-dev clean --cluster-name=<my cluster name>.

You will need to have the following tools installed to use this:

• Docker
• kind
• ko
• kubectl

Use local registry

If you would like to use the local Kind registry instead of a live one, do not include the registry-url flag when calling the CLI. It will default to using the local registry. But before running the CLI, you must add the following line to your /etc/hosts file first: 127.0.0.1 registry.local

Support Policy

This policy-controller's versions are able to run in the following versions of Kubernetes:

	policy-controller > 0.2.x
Kubernetes 1.22	✓
Kubernetes 1.23	✓
Kubernetes 1.24	✓
Kubernetes 1.25	✓

note: not fully tested yet, but can be installed

Release Cadence

We are intending to move to a monthly cadence for minor releases. Minor releases will be published around the beginning of the month. We may cut a patch release instead, if the changes are small enough not to warrant a minor release. We will also cut patch releases periodically as needed to address bugs.

Security

Should you discover any security issues, please refer to Sigstore's security policy.